Quantitative and qualitative models will be fit to the results of the proposed research in order to develop a systematic theory of information processing, attention, short-term memory, long-term memory, storage, search, retrieval and forgetting. The proposal is in two parts. The first will involve a "micro-analysis" of controlled and automatic processing as seen in attention and search. Automatic processing occurs when a process is learned and automatized in long-term memory after consistent training. In search tasks an automatic attention response can be learned when the targets are consistently mapped to responses; then detection will be parallel, efficient, and largely independent of the amount of simultaneous distracting information. Controlled processing is malleable, easy to set up, but time consuming, serial in nature, and highly dependent on load. In search tasks, controlled search will be serial and highly demanding of limited attention. The proposed studies will trace these two processes and their development through a micro-analysis of data from a small number of subjects trained in a wide range of search, detection and attention studies. The same model will be applied across these tasks; reaction time and accuracy measures, as well as visual and auditory processing, will be linked. The second part of the proposal will examine search and retrieval in short- and long-term memory. These studies will examine the basic mechanisms involved in short- and long-term forgetting. The models derived from the studies in the two sections will be linked in an overall theory.